Since it is undesirable to start a direct reversing marine engine unless all operating conditions for doing so are favorable, means should be provided for automatically preventing engine start until any undesirable conditions have been corrected.
Presently known means include directional valves for intercepting pneumatic control signals, during such time that an adverse condition exists and until such time that the adverse condition is corrected. One disadvantage of this method is that the interconnection of the control signal, which is normally a pneumatic graduated signal (depending upon the degree of operation, such as speed for example, being effected), by the directional valves, is that the graduating effect of the signal has either been diminished or nullified by the time it is unblocked by the directional valve. Another disadvantage of this presently known method is that the operation of the engine controller has no apprisal that the control has been intercepted.